Maritime survival capsule

ABSTRACT

A maritime survival capsule is shaped like a somewhat elongted egg, and has an inside shell which is moulded slightly smaller. Features of the capsule include: a front end porthole; a front end opening, for the tow line, anchor line, or sea anchor; a chain/rope locker, which, when a plastic bag liner is employed, also functions as a toilet; a ballast tank system which floods with water when the capsule is placed in water, an internal seating system; a multi-function device which functions as a dagger board/keel, a rudder, and a propulsion system; a conventional diaphragm-type bilge pump or pumps; special internal geometry which enables occupants to wedge themselves securely in place; an entry system comprised in pan of strategically placed handles inside the capsule; a multi-feature door system; a life supporting environmental system, dealing with the requirements for control of heat loss, humidity control, air exchange, and cooling; a submersible feature, which enables the capsule containing the occupants to be submerged and then launched safely from under water, either inadvertently, or intentionally; a fully circular profile, above and below the normal water line; a launching system which rigidly holds the capsule affixed to the vessel until the occupants have been boarded, with launching being automatic, through a hydrostatic release, or manually; miscellaneous compartments for stowing supplies; and foam flotation.

TECHNICAL FIELD

This invention relates to a maritime survival capsule, and variousfeatures thereof. The capsule is intended for emergency use, such aswhen a ship is sinking.

DISCLOSURE OF INVENTION

The capsule is shaped like a somewhat elongated egg, i.e. generallyelliptical, but with one end larger than the other it is approximately2.75 m long by 1.2 m diameter (9 feet long by 4 feet diameter) outside.It has an inside shell which is moulded slightly smaller, generally topermit about 3 cm (11/4 inches) of balsa core spacer.

General features observed on the capsule (starting from the smaller end,which is termed the bow) include:

1. A front end porthole, for visibility.

2. A front end opening, for the tow line, anchor line, or sea anchor.

3. A chain/rope locker, which, when a plastic bag liner is employed,also functions as a toilet.

4. A ballast tank system which floods with approximately 100 kg. (225pounds) of water when the capsule is placed in water.

5. A seat system designed ergonomically for comfort over extendedperiods.

6. A multi-function device which functions as a dagger board/keel, arudder, and a propulsion system.

7. Conventional diaphragm-type bilge pumps.

8. Special internal geometry which enables occupants to wedge themselvessecurely in place.

9. An entry system comprised in part of strategically placed handlesinside the capsule.

10. A multi-feature door system.

11. A life supporting environmental system, dealing with therequirements for control of heat loss, humidity control, air exchange,and cooling.

12. A submersible feature, which enables the capsule containing theoccupants to be submerged and then launched safely from under water,either inadvertently, or intentionally.

13. A fully circular profile, above and below the normal water line.

14. A launching system which rigidly holds the capsule affixed to thevessel until the occupants have been boarded, with launching beingautomatic, through a hydrostatic release, or manually.

15. Miscellaneous compartments for stowing supplies.

16. Foam flotation.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be described with reference to the accompanyingdrawings, in which:

FIG. 1 shows the capsule lying on its side, with the bottom visible;

FIG. 2 shows the hatch area, viewed from inside;

FIG. 3 shows the hull liner inverted;

FIG. 4 shows the dagger board fully forward with the blades or flapsclosed;

FIG. 5 shows the dagger board with the flaps opening, viewed frombehind;

FIG. 6 shows the dagger board with the flaps open, viewed from thefront;

FIG. 7 the hatch area, viewed from the inside, with the hatch closing;

FIG. 8 is an external view of the capsule with the hatch removed;

FIG. 9 shows the moulded inner hull shell from the hatch end;

FIG. 10 shows the view in through the hatch;

FIG. 11 shows the seat for the last man in, with the hatch opening aboveand behind;

FIG. 12 shows the side view of capsule, with its profile and smoothlines;

FIG. 13 shows the dagger board with flaps closed and the starter-watertrap, which starts blades or flaps opening on a forward stroke of theoperating handle;

FIG. 14 is of the underside of the hull, showing the dagger box, plusfour recessed water ballast holes (not drilled) to ballast tanks underthe side seating;

FIG. 15 shows the dagger board moulds, showing one flapper blade backand the internal shaft lock;

FIG. 16 shows the inner and outer hull;

FIG. 17 shows the hatch closed;

FIG. 18 shows a person prone in the capsule;

FIG. 19 shows a side view of the capsule with the hatch removed;

FIG. 20 is of the upper mould, showing the balsa core and hatchway;

FIG. 21 is a view of the hull, showing the bonding flange, balsa core,dagger box and two of four water ballast inlets;

FIG. 22 shows the dagger board with flaps fully opened, viewed frombehind;

FIG. 23 shows typical cross-seating; and

FIG. 24 shows the hatch entry system, without rubber seals and lockingpins are not in place.

BEST MODE FOR CARRYING OUT THE INVENTION

The capsule 1 is shaped like a somewhat elongated egg, and has an insideshell which is moulded slightly smaller. As listed above, principalfeatures of the preferred embodiment of the capsule include: a front endporthole (not illustrated); a front end opening (not illustrated), forthe tow line, anchor line, or sea anchor; a chain/rope locker 2, which,when a plastic bag liner is employed, also functions as a toilet;ballast tanks 3 which flood with water when the capsule is placed inwater; internal seating and geometry, described below in greater detail;a multi-function deride 4 which functions as a dagger board/keel, arudder, and a propulsion system; a conventional diaphragm-type bilgepump or pumps (not illustrated); a multi-feature door system 5; a fullycircular profile, above and below the normal water line; miscellaneouscompartments 6 for stowing supplies; and foam flotation 7.

Some of the more inventive features of the capsule are described ingreater detail below. The section numbers correspond to the numbers forthe features listed above in the section "Disclosure of Invention":

2. Small End (bow) Opening

The bow opening must be sealed from the outside, so that external waterpressure will tend to seat its plug solidly. However, the hole must alsobe tapered in a way such that at least a portion of it has the "smallend pointing out". This enables a towing plug to be inserted to graspthe tow line, and distribute towing forces to the shell in a safemanner.

Basically, these geometrically conflicting requirements can be met withthe equivalent to "two bath tub plugs back to back".

The outer plug, with its small end pointing inward, will be held inplace when the capsule is being stowed on deck by a flag pin which isreleased as the capsule is launched. In this manner, it is not possiblefor water to enter the capsule through the bow prior to launching. Theplug would be made from an elastomeric material which was cast around adouble-eyed rod, to which was attached the sea anchor line (outside) andthe bow line (inside).

The inner plug, with its small and pointing outward, would be made frommuch harder and stronger material, and would have a "slider hole",through which the bow line would freely pass. When it was desired totake a tow, or otherwise lock the rope to prevent payout, a rope lockwould be employed to prevent rope outfeed.

An alternative to the above is to employ a double eyed through bolt,which is locked inside the capsule during stowage, and which can bereleased at any time by an occupant inside the capsule.

3. The Chain/Rope Locker and Toilet

A compartment 2 in the bow serves as a stowage place for the roperequired for the towline/anchor system. In bad weather conditions, whenbowel movements cannot be made from the stern of the capsule, rope canbe removed from the locker, and it can be fitted with a plastic bagliner to permit its use as a toilet. The shape of the inside of the bowis such that the person using the toilet can wedge himself in placeagainst the upper section of the capsule. This is important in a heavyseas condition. It has also been found that the fetid odour problem issurprisingly small when using the plastic bag method for fecal mattercontainment.

4. Ballast Tank System

The capsule employs ballast tanks 3 under the side seats, which aredesigned to provide adequate strength to prevent rupture when thecapsule is submerged. FIG. 14 shows four recessed water ballast holes 20(not drilled) to the ballast tanks. The tanks provide approximately 100kg. (230 lbs.) of instant ballast.

5. Seat System (See also Sec. 8)

The seat system design is unusual, in that in has a very steep seatangle. While most chairs and seats have an angle to the vertical in therange of 80 to 90 degrees, the seat employs an angle of between 45degrees to 80 degrees from the vertical. Two major advantages ensure:

1. The body can adopt the fetal position, which is comfortable forextended periods, while being provided with a large bearing area on theupper leg, or thigh muscle, on which the individual sits.

2. In this position, in conjunction with the back and foot restsprovided, the individual can lock himself in place, with very littleeffort and stress, to resist movement, when the capsule is tossed byheavy seas.

The seating includes bench areas 8, and a seat 9 beneath the hatch forthe last man into the capsule.

6. Dagger Board/Keel/Rudder/Propulsion System

The capsule employs an especially useful device 4 which serves fournecessary functions, while being simple and durable. All this isaccomplished with only one through hull penetration.

The device is basically a dagger board which is retracted up into thedagger board box 10 by rotating it. It remains outside the capsule, butit can be partially retracted, to retain a conventional keel effect foraxial stability, or it can be fully tucked up within the dagger boardbox, to permit perfect retention of the circular profile of the capsule,when desired.

Attached to each side of the basic dagger board are two flaps or cheeks11 which are attached by hinges. A starter-water trap area 12 isprovided to start the blades or flaps opening on a forward stroke of theoperating handle 13. By rotating the operating handle toward the stern,the dagger board is deployed, but while it is being rotated toward thebow, the flaps for cheeks splay apart to form a shape which catches thewater, and enables rearward thrust, and acts as a propulsion system. Thedevice is especially effective if the ends of the cheek flaps contactthe entry of the daggerboard box prior to the end of the thrust stroke.This causes partial closure of the cheek flaps, which causes the watercontained between the cheek flaps and the dagger board body toaccelerate prior to exit. The result is a significant increase inpropulsive thrust.

The same device can also act as a rudder, to provide steerage for thecapsule, Simply by having the occupants shift their weight to the sideof the capsule to which it is desired to change direction.

8. Internal Geometry and Seats (See also Sec. 5)

Comfort in a confined space over an extended period is very important ina craft of this nature. The proportions of the interior of the capsulehave been designed to enable the occupants to remain comfortable over anextended period, with a minimum expenditure of energy and a maximumdegree of relaxation. The key, in this ergonomic design, is the abilityof the occupant to adopt a semi-fetal, semi-supine position, which isvery restful.

The specific features are:

1. A radius of curvature for back and head support of about 0.6 m (2feet)

2. An angle for seat back 14 which is between 45 degrees and 80 degreesfrom the vertical

3. A foot rest 15 which is located at a suitable position.

This geometry permits a person to effectively lock himself in place, asshown in FIG. 18, with little effort required to prevent being thrownabout from capsule movement.

This geometry will work as long as the coefficient of friction betweenthe person's clothes and the capsule wall is greater than a certainamount.

The seats are unique, in that they are very comfortable while being verynarrow. While conventional seats have a dimension in the direction alongthe thighs of 30 to 45 cm (12 to 18 inches), these seats can be asnarrow as 20 cm (8 inches) along the thigh and still be verycomfortable. It has been found that two additional factors are importantin seat design:

1. The height of the back support 14; and

2. The coefficient of friction between the person's clothing and theseating system.

Also important are:

1. The radius of the curve connecting the back support element with theseat support element; and

2. The radius of curvature of the far end of the seat, where it leavesthe thigh, and the angular distance through which it is employed.

Further work is necessary to determine the actual limits of seatgeometry.

It is interesting and important to note the importance of thecoefficient of friction of the seat and back support areas. On the onehand, having an overall geometry which enables the person to comfortablywedge himself in place to prevent sliding and movement while requiringonly a low coefficient of friction is advantageous, in that a low levelof effort is necessary to create the normal forces which in turn lead tothe restraining frictional forces.

On the other hand, a high coefficient of friction enables the lower backarea of the person to become effective and useful in carrying thepersons weight, thus permitting an apparently smaller seat area.

10. Multi-feature Entry Door System

The entry door or hatch 5, is unusual for a number of reasons:

1. Because of a double lip arrangement 16 around the perimeter of thehatch and its opening, the hatch acts to strengthen the shell opening,which is necessary for entry to the capsule, but additionally, itenables the door to be locked in place very securely with only two smalland simple locking pins.

2. It is double walled, and curved for strength.

3. It employs an integral porthole 17, to provide a view to the outside,and to admit light.

4. It is hinged on the bottom, via a three-point binge 18, so that whenopened, it folds downward.

5. It employs a "fold-out" extension step 19 to permit easy entry,whether from a deck, or from the water.

6. Two water seals can be employed in a manner where external pressureon the door acts to enhance the water seal effect.

11. Life Support Environmental System

Being a totally enclosed capsule, it must have a positive life supportsystem enabling the occupants to survive expected conditions. Featureswhich are addressed include:

1. Retention of heat, for cold water situations

2. Humidity control

3. Air exchange, to meet physiological oxygen requirements

4. Air exchange, to meet the ventilation requirements for sweeping awayfoul odours

5. Control of heat build-up

12. Submersible Feature

The capsule has been designed with adequate strength, and withwaterproof openings, to permit submergence without endangering theoccupants. Indeed, the preferred launch method is to wait until the shiphas settled below water level prior to releasing the capsule. Two levelsof deployment are employed: manual, and automatic. The capsule isautomatically deployed by means of a hydrostatic release device whichdisables the restraining system when it sinks to a depth of between 1meter and 4.5 meters.

This appears to be an unusual method of launching a life-saying craft.However, to avoid being classed as a submarine, which would entailenormous strength and environmental maintenance requirements, it isnecessary to specify limits to submersibility, in terms of:

1. Maximum recommended operating depth (say 15 feet, or 4.5 meters)

2. Maximum recommended submergence time (say 15 seconds)

13. Fully Circular Profile

The fully circular profile, below and above the water line, appearsunique. This profile is surprising, in that conventional thinkingsuggests that there be protruding fins and such like appurtenances tostabilize the capsule. While this is true for a large vessel, underpower, and having a relatively large profile above water, it is not truefor a small craft, unpowered, and with an above-water profile which isrelatively small in comparison to its below-water profile.

The proposed family of capsules will be fully circular in profile, i.e.at each profile station, the capsule will appear circular in crosssection. While the centres of the profile circles can be above or belowan imaginary horizontal centre line, it is generally preferred that theybe on this imaginary line. The circular profiles should preferably besmaller at both ends than at the middle, to present a blunted profile tothe wind and the water. Additionally, it is preferred that the averagesize of the circular profile sections be larger at the stern end of thecapsule than at the bow end. In contrast to a shape which would beelliptical if the bow and stern profiles were equal, the preferred shapeattained is somewhat like an egg.

The general advantages of this shape are strength, stability, and thelack of protruberences to act as points of force concentration, eithermechanical or hydrodynamic. A specific advantage of this shape is thatit enables installation of a hatch which is disproportionately large forthe general geometry, while permitting it to blend in perfectly with theoverall geometry.

14. Launching System

As touched on in Section 12 above, the launching system will permitrelease of the capsule from its mounts either when above or below water,manually or automatically, or from inside or from outside the capsule.

When launched from above water, it is released and is simply allowed tofall in an unconstrained or unsupported manner. This is practical, inthat there is no danger of being swamped, overturned, or sunk because ofhaving taken on water. The limit to the height through which the capsulecan be dropped is determined by the g forces which the occupants willexperience on impact with the water. Instrumented drop tests willdetermine how the capsule penetrates the water when dropped, and the gforces which result.

INDUSTRIAL APPLICABILITY

This invention provides a maritime survival capsule, intended foremergency use, such as when a ship is sinking.

I claim:
 1. A maritime survival capsule, comprising an outer shell whichis generally egg-shaped, thus having a generally circular cross-sectionwith a relatively broad stern and a narrower bow, and a sealable entryhatch across a hatch opening through an upper portion of said shelladjacent said stern, pivotally attached to said shell via a hingemechanism between said hatch and said shell, adjacent a bottom edge ofsaid hatch and said hatch opening, such that when opened, said hatchfolds downwardly and away from said hatch opening, said hatch having anextension step pivotally mounted adjacent an upper edge thereof,pivotable away from said hatch so as to extend downwardly and away fromsaid hatch when said hatch is open.
 2. A capsule as recited in claim 1,where said capsule has inner and outer shells, and has ballast tanksbetween said inner and outer shells, which flood with water when thecapsule is placed in water.
 3. A capsule as recited in claim 1, furthercomprising seating within said capsule integral with said capsule,including bench areas along either side thereof, a foot well extendingdownwardly between said benches, and a seat under said hatch for seatingthe last person to enter the capsule.
 4. A capsule as recited in claim2, further comprising seating within said capsule integral with saidcapsule, including bench areas along either side thereof, a foot wellextending downwardly between said benches, and a seat under said hatchfor seating the last person to enter the capsule.
 5. A capsule asrecited in claim 4, where said bench seats are defined by said innershell, and where said ballast tanks defined between said inner and outershells beneath said bench seats.